Phenylmercuric compound

Cinnabar Electron tubes containing mercury Mercuric salt Mercurous compound Mercury compound, liquid, n.o.s, 6.1 Mercury compound, solid, n.o.s., 6.1 Mercury contained in manufactured articles, 8 Mercury vapour tubes Phenylmercuric compound, n.o.s., 6.1 Quicksilver 

Mercury compounds retain the toxicity of their parent metal. Many are unstable, including mercurous compounds in which mercury exists as Hg or Hg(I) or as a mercury salt like mercuric salts in which mercury exists as 

Amalgams, see Metals, Alloy, p.151 Compound, see Terminology, Compound, p.234 

Liquid, see Terminology, Liquid, p.241 Mercury-based pesticide, see Pesticides, p.179 

The processing of bauxite aluminium ore (hydrated alumina oxides) exemplifies these processes. In the Bayer process hot concentrated sodium hydroxide dissolves alumina which is subsequently separated and crystallized as aluminium hydroxide (hydrometallurgy). This is calcined to anhydrous alumina (pyrometallurgy) before being reduced in the Hall process (electrometallurgy) wherein alumina serves as the electrode from which elemental aluminium is deposited on the cathode. 

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Ingversen J, Andersen VS. Transfer of phenylmercuric compounds from dilute aqueous solutions to vials and rubber closures. Dansk Tidsskr Farm 1968 42 264-271. 

Incompatible with aluminum and other metals, strong oxidizing agents, strong acids and bases, sodium chloride solutions, lecithin, phenylmercuric compounds, quaternary ammonium compounds, thioglycolate, and proteins. The presence of sodium metabisulfite, edetic acid, and edetates in solutions can reduce the preservative efficacy of thimerosal. ... 

Berlin M. 1963. Renal uptake, excretion and retention of mercury Part II. A study in the rabbit during infusion of methyl- and phenylmercuric compounds. Arch Environ Health 6 626-633. 

Marone G, Kagey-Sobotka A, Lichtenstein LM (1981) Control mechanisms of histamine release from human basophils in vitro The role of phospholipase A 2 and of lipoxygenase metabolites. Int Arch Allergy Appl Immunol [Suppl 1] 66 144 Mathews KP, Pan PM (1968) Immediate type hypersensitivity to phenylmercuric compounds. Am J Med 44 310... 

Micro-organisms replicate only in the presence of water. The activity of preservatives depends therefore on the concentration of the free and active form in the aqueous phase of the preparation. Free refers to the binding that some preservatives can have with active substances, excipients or packaging materials. Examples of the binding of preservatives are the adsorption of phenylmercuric compounds to rubber stoppers, the adsorption of benzalkonium chloride to silicon rubber tubes and to cellulose nitrate-membrane filters, the solubilisation of methyl parahydroxybenzoate by polysorbate 80 [49] and by sodium lauiyl sulfate [50] and the migration (distribution) towards the lipid phase of methyl parahydroxybenzoate in emulsions. 

The second area of activity is that of metallo-de-diazoniation, the reactions that are the subject of this section. This activity began in 1929 when Nesmeyanov (1929a, b) and McClure and Lowy (1929, 1931) independently found that phenylmercuric chloride is formed if mercury is vigorously agitated with an aqueous solution of ben-zenediazonium chloride (Scheme 10-86). Analogous compounds based on elements of groups V and Vb (P, As, Sb, and Bi) have also been found, some even before those of mercury. 

Examples of preservatives are phenylmercuric nitrate or acetate (0.002% w/v), chlorhexidine acetate (0.01 % w/v), thiomersal (0.01 % w/v) and benzalkorrium chloride (0.01 % w/v). Chlorocresol is too toxic to the comeal epithehum, but 8-hydroxyquinoline and thiomersal may be used in specific instances. The principal considerahon in relation to antimicrobial properties is the activity of the bactericide against Pseudomonas aeruginosa, a major source of serious nosocomial eye infections. Although benzal-konium chloride is probably the most active of the recommended preservatives, it cannot always be used because of its incompatibility with many compounds commonly used to treat eye diseases, nor should it be used to preserve eye-drops containing anaesthetics. Since benzalkonium chloride reacts with natural mbber, silicone or butyl rabber teats should be substituted. Since silicone mbber is permeable to water vapour, products should not be stored for more than 3 months after manufacture. As with all mbber components, the mbber teat should be pre-equilibrated with the preservative prior to... 

The degradation of phenylmercuric acetate to benzene, methylmercuric chloride to methane, and ethylmercuric chloride to ethane and Hg + is apparently carried out by different enzymes from the plasmid-carrying Escherichia coli strain K12 (R831) (Schottel 1978) and Pseudomonas sp. Resistance to organic mercury compounds has also been found in clinical isolates of nontuber-culous, rapidly growing mycobacteria (Steingrube et al. 1991) and can present a challenge in the clinical environment. 

Substances that have been used as preservatives for disperse systems include chlorocresol, chlorobutanol, benzoates, phenylmercuric nitrate, parabens, and others [76,77]. The use of cationic antimicrobial agents such as quaternary ammonium compounds (e.g., benzalkonium chloride) is contraindicated in many cases because they may be inactivated by other formulation components and/or they may alter the charge of the dispersed phase. Clay suspensions and gels should be adequately preserved with nonionic antimicrobial preservatives. The use of preservatives is generally limited to products that are not intended for parenteral use. Intravenous injectable... 

Some interesting electron-transfer reactions of sodium naphthalide have recently been reported. Reaction with phenylmercuric chloride or benzylmercuric chloride gives better than 70% yields of the symmetric diphenyl- or dibenzylmercury compounds. Solutions of alkali metals in HMPA lead to the same results (88). Evidence for the reaction of sodium naphthalide with methylene halides to give methylene anion radical, CH2T, has recently appeared (22). 

Mercuration- Thallation. Mercuric acetate and thallium trifluoroacetate react with benzene to yield phenylmercuric acetate [62-38-4] or phenylthallic trifluoroacetate. The arylthallium compounds can be converted into phenols, nitriles, or aryl iodides (31). 

The commercial production of mercury fungicides from organolead compounds is based on patents by Kharasch 184,185). The mercury compounds are used in the disinfection of seeds and grains. Typical compounds are ethylmercuric chloride, ethylmercuric sulfate, ethyl-mercuric phosphate, phenylmercuric acetate, and compounds derived from substituted phenols and ureas. The manufacture of these compounds was reviewed by Whelen in 1957 310>. The alkylation reaction is a general reaction, and a number of additional patents has been issued on methods similar to Whelen s. A representative equation is ... 

It seems to be certain that the oxynitration reaction in the presence of mercury salts proceeds through the formation of phenylmercuric nitrate. The isolation of phenylmercuric nitrate from a reaction mixture in dilute nitric acid by several authors (Carmack and his co-workers [135], Titov and Laptev [71], and also Bro-ders [124]) favours this view. If an intermediate nitroso compound is formed in the reaction its formation should be ascribed to the reaction between phenylmercuric nitrate and nitrous acid. This view, based on earlier experiments of Baeyer [136], Bamberger [137], Smith and Taylor [137a], has since been confirmed by Westheimer, Segel and Schramm [138], who considered the nitroso compound formed from an organo-mercuric compound to be the principal intermediate product in the Wolffenstein and Boters reaction. 

Using phenylmercuric chloride. Thirty grams of this compound and 100 grams of arsenious chloride are heated together on the water-bath for four to five hours. The product is then filtered off and the filtrate distilled in vacuo, excess or arsenious chloride being removed by first distilling at 100° C. ... 

The degree of ionization of acidic and basic antimicrobial agents depends on pH. Some compounds are active only in the unionized state (e.g., phenolics) whereas others are preferentially active as either the anion or cation. It therefore follows that the activity of a particular concentration of an agent will be enhanced at a pH that favors the formation of the active species. Thus, cationic antibacterials such as acridines and quaternary ammonium compounds are more active under alkaline conditions. Conversely, phenols and benzoic acid are more active in an acid medium. Chlorbutol is less active above pH 5 and unstable above pH 6. Phenylmercuric nitrate is only active at above pH 6 whereas thiomersal is more active under acid conditions. The sporicidal activity of glutaraldehyde is considerably enhanced under alkaline conditions whereas hypochlorites are virtually ineffective at above pH 8. 

Aryl mercurials that have been used medicinally include phenylmercuric acetate, phenylmercuric nitrate, nitromersol, thiomersal, merbromin (mercurochrome), and mercurobutol. These compounds are variously used as preservatives in drugs, including vaccines, for skin disinfestation, the treatment of infections of the skin and mucosa, and in contraceptive jellies and hemorrhoidal remedies they have also been used in some cosmetics. The aryl mercurials are better absorbed across the mucous membranes than most inorganic mercury salts. 

The use of mercurials in the eye can lead to a bluish-gray deposit of mercuric oxide on the eyelids, conjuncti-vae, and Descemet s layer. Phenylmercuric nitrate used in a 0.004% concentration can cause mercuria lentis. Mercurial compounds have been found in the aqueous humor, having penetrated the eye from hydrophilic-gel contact lenses preserved with thiomersal. Although it remains to be established whether deposition of mercury in the eye is clinically important, the concentrations found are similar to those reported in cases of systemic poisoning by organic mercurials (64). 

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